The present invention relates to a data transfer control device and an electronic instrument.
In recent years, a high-speed serial transfer interface such as a low voltage differential signaling (LVDS) interface has attracted attention as an interface aiming at reducing EMI noise or the like. In such a high-speed serial transfer, data is transferred by causing a transmitter circuit to transmit serialized data using differential signals and causing a receiver circuit to differentially amplify the differential signals (JP-A-2001-222249).
An ordinary portable telephone includes a first instrument section provided with buttons for inputting a telephone number or a character, a second instrument section provided with a main liquid crystal display (LCD), a sub LCD, and a camera, and a connection section (e.g. hinge) which connects the first and second instrument sections. The number of interconnects passing through the connection section can be reduced by transferring data between a first substrate of the first instrument section and a second substrate of the second instrument section by serial transfer using differential signals.
The following method may be considered as a method of realizing serial transfer through the connection section. Specifically, a host device (e.g. CPU or baseband engine) provided in the first instrument section outputs interface signals (e.g. RGB interface signals) to a host-side data transfer control device. Then, the host-side data transfer control device packetizes the interface signals and transmits the resulting packet to a target-side data transfer control device provided in the second instrument section. The target-side data transfer control device reproduces the interface signals based on the received packet, and outputs the interface signals to an LCD provided in the second instrument section.
However, when realizing serial transfer by such a method, reception of the packet is adversely affected when noise is imposed on the serial transmission line. In particular, when the host device outputs an RGB interface synchronization signal (vertical synchronization signal or horizontal synchronization signal) and the target reproduces the synchronization signal, a problem such as a change in display position occurs when noise is imposed on the serial transmission line.